#include "stdio_impl.h"
#include <sys/uio.h>
#ifdef OS_OPTION_NUTTX_VFS
#include <nuttx/sys/sys_uio.h>
#include <nuttx/sys/sys_unistd.h>
#endif

size_t __stdio_read(FILE *f, unsigned char *buf, size_t len)
{
#ifdef OS_OPTION_NUTTX_VFS
	struct iovec iov[2] = {
		{ .iov_base = buf, .iov_len = len - !!f->buf_size },
		{ .iov_base = f->buf, .iov_len = f->buf_size }
	};
	ssize_t cnt;

	cnt = iov[0].iov_len ? sys_readv(f->fd, iov, 2)
		: sys_read(f->fd, iov[1].iov_base, iov[1].iov_len);
	if (cnt <= 0) {
		f->flags |= cnt ? F_ERR : F_EOF;
		return 0;
	}
	if (cnt <= iov[0].iov_len) return cnt;
	cnt -= iov[0].iov_len;
	f->rpos = f->buf;
	f->rend = f->buf + cnt;
	if (f->buf_size) buf[len-1] = *f->rpos++;
	return len;
#else
	return 0;
#endif /* OS_OPTION_NUTTX_VFS */
}
